The present invention relates to a hand tool of the type in which motor can rotate in clockwise and counterclockwise directions and which includes a device for the displacement of brushes wiping on a collector.
In the hand tools of the foregoing type, displacements of the brushes are performed by switching over of the direction of the armature of the motor in order to obtain an output comparable with that of the universal motors with reversing directions of rotation. Expensive devices have been employed for the displacement of the brushes, in which devices hand-laid and hand-connected conduits have been required. The universal electric motors provided with such devices have not been, however, suitable for mass production.